Camera assembly and assembling method thereof

ABSTRACT

A camera assembly includes a motor configured to generate a driving power; a motor shaft that extends from the motor, such as to define a first axis, and is configured to rotate by the driving power of the motor; a pulley configured to rotate on a second axis, that is spaced from the first axis, according to rotation of the motor shaft; a belt configured to couple the motor shaft and the pulley, and convert the rotation of the motor shaft to rotation of the pulley, and tension of the belt applies a force to the motor shaft in a direction towards the second axis; a camera module configured to be mounted on the pulley and rotate together with the pulley; and an elastic body configured to apply a biasing force to the motor shaft such as to bias the motor shaft in a direction away from the second axis.

CROSS-REFERENCE TO THE RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/201,786, filed on Mar. 15, 2021, which claims priority from KoreanPatent Application No. 10-2020-0031832, filed on Mar. 16, 2020, in theKorean Intellectual Property Office, the disclosures of which areincorporated herein in their entireties by reference.

BACKGROUND 1. Field

Embodiments of the present disclosure relate to a camera assembly, andmore specifically, to a camera assembly for transmitting via a timingbelt the driving power from a motor to an output shaft coupled to acamera module.

2. Description of Related Art

A surveillance camera supporting pan/tilt/zoom functions may transmitdriving power generated from a stepping motor to the output shaft. Inorder to transmit such a driving power, a timing belt is normally usedto couple a motor shaft of the stepping motor and the output shaft.

By using the timing belt as a power transmission structure, a user caneasily adjust a gear ratio and an axial distance. However, in terms ofthe power transmission, there is an important requirement that thetension of the timing belt should be maintained in an optimal state. Incase that the tension of the timing belt is too low, there might beconcerns about shakings of a camera and slips or malfunctioning of amotor. On the contrary, in a case where the tension of the timing beltis too high, there might be concerns about wear-out or damages ofcomponents in the camera assembly and a power reduction of the motor dueto a load increase.

In this regard, there might be two schemes to solve the problem. Thefirst scheme is to maintain the tension of the timing belt within adesigned range by strict quality controls on dimensions and clearancesof the related components. In addition, the second scheme is to adjustthe tension of the timing belt by manual controls on the axial distanceduring the assembling process.

According to the first scheme, it is necessary to manage the size,clearance, and axial distance of a pulley in order to maintain thetension of the timing belt, but it inevitably results in a cost increasefor quality controls on some components and a risk of defectiveproducts.

On the other hand, the second scheme has an advantage of reducing adefect rate by lowering the standard of clearance management on therelated components when adjusting the axial distance during anassembling process for managing the tension of the timing belt. However,it requires an additional dedicated device for applying a proper tensionduring the assembling process. Additionally, it is inappropriate for arework and does not address the problem that the axial distance changesdue to an external force after completing the assembling process.

Further, even after a proper tension is applied to the timing belt, adecentering or an eccentricity may be caused due to a setting angle ofthe camera assembly and surroundings around the camera assembly, whichmakes the tension of the timing belt change from the designed value.

SUMMARY

According to embodiments of the present disclosure, a camera assembly isprovided in which tension of a timing belt is adaptively adjustedwithout unnecessary efforts such as strict clearance managements forcomponents during an assembling process or adjustments of an axialdistance.

Also provided is a camera assembly in which tension of a timing belt isadaptively adjusted in spite of changes in a setting angle of the cameraassembly or surroundings around the camera assembly.

However, aspects of embodiments of the present disclosure are notrestricted to those set forth herein. Various other aspects ofembodiments of the present disclosure will become more apparent to oneof ordinary skill in the art to which the embodiments of the presentdisclosure pertain by referencing the detailed description of theembodiments given below.

According to one or more embodiments, a camera assembly is provided. Thecamera assembly includes: a motor configured to generate a drivingpower; a motor shaft that extends from the motor, such as to define afirst axis, and is configured to rotate by the driving power of themotor; a pulley configured to rotate on a second axis, that is spacedfrom the first axis, according to rotation of the motor shaft; a beltconfigured to couple the motor shaft and the pulley, and convert therotation of the motor shaft to rotation of the pulley, and tension ofthe belt applies a force to the motor shaft in a direction towards thesecond axis; a camera module configured to be mounted on the pulley androtate together with the pulley; and an elastic body configured to applya biasing force to the motor shaft such as to bias the motor shaft in adirection away from the second axis, wherein the force and the biasingforce are balanced such that a distance between the first axis and thesecond axis is adaptively adjusted.

According to an embodiment, the camera assembly further includes: a baseconfigured to be fixed at a side of a housing of the camera assembly;and a movable body configured to be fixedly coupled to the motor androtatably mounted on the base.

According to an embodiment, the camera assembly further includes: afixed shaft configured to rotatably mount the movable body on a firstpoint of the base; and at least one movable shaft configured to becoupled to the base at a respective second point, that is spaced fromthe first point, each of the at least one movable shaft received in acorresponding slot in the movable body such as to support sliding motionof the movable body.

According to an embodiment, the camera assembly further includes: afixed shaft configured to rotatably mount the movable body on a firstpoint of the base; and at least one movable shaft configured to becoupled to the movable body at a respective second point, that is spacedfrom the first point, each of the at least one movable shaft received ina corresponding slot in the base such as to support sliding motion ofthe movable body.

According to an embodiment, in a case where the movable body rotatesaround the fixed shaft, the at least one movable shaft is received inthe corresponding slot, without interference from the correspondingslot, while supporting the sliding motion of the movable body.

According to an embodiment, the at least one movable shaft includes twomovable shafts that are received in a first corresponding slot and asecond corresponding slot, respectively.

According to an embodiment, an end of the elastic body is coupled to thebase and another end of the elastic body is coupled to the movable bodysuch as to cause tension in the elastic body.

According to an embodiment, a point where the end of the elastic body iscoupled to the base is farther than a point where the another end of theelastic body is coupled to the movable body from the second axis.

According to an embodiment, the base has a first hollow and the movablebody has a second hollow axially corresponding to the first hollow, andthe motor shaft passes through the first hollow and the second hollow.

According to an embodiment, the belt engages with a distal end of themotor shaft that is passed through the first hollow and the secondhollow.

According to an embodiment, a pinion is provided at the distal end ofthe motor shaft and gear teeth are provided at an outer circumferentialsurface of the pulley, and threads defined at an inner surface of thebelt engage with the pinion and the gear teeth.

According to an embodiment, a head of the fixed shaft is positionedhigher than the movable body mounted on the base such as to allow themovable body to rotate around the fixed shaft relative to the base whilethe fixed shaft is coupled to the base.

According to an embodiment, the camera assembly further includes afastener configured to fixedly couple the motor and the movable body,wherein a head of the fastener is received in a through hole with aclearance, such as to allow a contact between the base and the movablebody without interrupting turning motion of the movable body withrespect to the base.

According to one or more embodiments, a camera assembly is provided. Thecamera assembly includes: a motor configured to generate a drivingpower; a motor shaft that extends from the motor, such as to define afirst axis, and is configured to rotate by the driving power of themotor; a pulley configured to rotate on a second axis, that is spacedfrom the first axis, according to rotation of the motor shaft; a beltconfigured to couple the motor shaft and the pulley, and convert therotation of the motor shaft to rotation of the pulley; a camera moduleconfigured to be mounted on the pulley and rotate together with thepulley; and an elastic body configured to apply a biasing force to themotor shaft such as to bias the motor shaft in a direction away from thesecond axis; a housing; a base fixed on the housing; and a movable bodyfixedly coupled to the motor and rotatably coupled to the base.

According to an embodiment, the camera assembly further includes: afixed shaft configured to rotatably mount the movable body on a firstpoint of the base; and a movable shaft configured to be coupled to thebase at a second point, that is spaced from the first point, andreceived in a corresponding slot in the movable body such as to supportsliding motion of the movable body.

According to an embodiment, the camera assembly further includes: afixed shaft configured to rotatably mount the movable body on a firstpoint of the base; and a movable shaft configured to be coupled to themovable body at a second point, that is spaced from the first point, andreceived in a corresponding slot in the base such as to support slidingmotion of the movable body.

According to an embodiment, an end of the elastic body is coupled to thebase and another end of the elastic body is coupled to the movable bodysuch as to cause tension in the elastic body.

According to an embodiment, a head of the fixed shaft is positionedhigher than the movable body mounted on the base such as to allow themovable body to rotate around the fixed shaft relative to the base whilethe fixed shaft is coupled to the base.

According to one or more embodiments, a method for assembling a cameraassembly is provided. The method includes: fixedly coupling a motor to amovable body; rotatably coupling the movable body to a base; installingan elastic body such that two ends of the elastic body are interposedbetween the movable body and the base; fixedly mounting the base on ahousing; and coupling, using a timing belt, a motor shaft to a pulley,the motor shaft extending from the motor and passing through a hollow ofthe movable body and a hollow of the base, and the pulley having acamera module mounted thereon.

According to an embodiment, the method further includes balancingtension of the timing belt with a biasing force of the elastic body,wherein the tension of the timing belt applies a force to the motorshaft in a direction towards a rotation axis of the pulley, and thebiasing force of the elastic body biases the motor shaft in a directionaway from the rotation axis of the pulley.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an assembled perspective view of a camera assembly accordingto an embodiment.

FIG. 2 is an exploded perspective view of the camera assembly accordingto an embodiment.

FIG. 3 is a top view of the camera assembly according to an embodiment.

FIG. 4 is a top view showing a base, a movable body, and an elastic bodyof the camera assembly according to an embodiment.

FIG. 5 is a drawing illustrating a connection between a movable body andthe base according to an embodiment.

FIG. 6 is a view of the camera assembly without the lower case.

FIG. 7 is a longitudinal sectional view taken from the camera assemblyof FIG. 6 along the vertical direction.

FIG. 8 is a bottom view of the camera assembly according to anembodiment without a lower case.

DETAILED DESCRIPTION

Benefits and features of embodiments of the present disclosure, andmethods for accomplishing the same will become apparent with referenceto embodiments described below in detail in conjunction with theaccompanying drawings. However, the embodiments disclosed herein are allexample embodiments, and thus, the disclosure is not limited to theseembodiments disclosed below, and may be implemented in various forms.The example embodiments are merely provided to make the disclosurecomplete and to fully inform the scope of the disclosure to thoseordinarily skilled in the art. Like reference numerals refer to likeelements throughout the specification.

Unless otherwise defined, all terms (including technical and scientificterms) used herein may be used in a sense that may be commonlyunderstood by those of ordinary skill in the art. In addition, the termsdefined in the commonly used dictionaries should not be ideally orexcessively interpreted unless they are specifically defined clearly.

The terms used herein are for the purpose of describing embodiments andare not intended to be limiting of the disclosure. Herein, the singularalso includes the plural unless specifically stated otherwise in thephrase. The term “comprises” and/or “comprising” as used herein does notexclude the presence or addition of one or more other components inaddition to the mentioned components. As used herein, expressions suchas “at least one of,” when preceding a list of elements, modify theentire list of elements and do not modify the individual elements of thelist. For example, the expression, “at least one of a, b, and c,” shouldbe understood as including only a, only b, only c, both a and b, both aand c, both b and c, or all of a, b, and c.

In the following description, when an element is referred to as being“above” or “on” another element, it may be directly on the other elementwhile making contact with the other element or may be above the otherelement without making contact with the other element.

Hereinafter, non-limiting example embodiments of the present disclosurewill be described in detail with reference to the accompanying drawings.

FIG. 1 is an assembled perspective view of a camera assembly 100according to an embodiment and FIG. 2 is an exploded perspective view ofthe camera assembly 100. camera assembly 100 may include a motor 110,pulley 120, a timing belt 130, an elastic body 140, a base 150 and amovable body 160.

The driving power generated by the motor 110 may be transmitted to themotor shaft 115 which rotates by the driving power of the motor 110around a first axis Ax. In this regard, the motor 110 may connect to apower supply (not shown) via terminals 113 in order to receive powerfrom the power supply.

Such driving power can be transmitted via a timing belt 130 to a pulley120 which rotates around a second axis Bx and is spaced from the firstaxis Ax. Specifically, the timing belt 130 couples the motor shaft 115and the pulley 120, and converts the rotation of the motor shaft 115 tothe rotation of the pulley 120. Thus, a portion of the timing belt 130that is proximate to the first axis Ax is coupled to the motor shaft115, and another portion of the timing belt 130 surrounding the secondaxis Bx is coupled to the outer circumferential surface of the pulley120.

A bracket 170 on which a camera module (not shown) is mounted is fixedlycoupled with the pulley 120 and rotates together with the pulley 120.Thus, the camera module rotates according to the rotation of the pulley120.

In this regard, the elastic body 140 applies a biasing force in thedirection in which the first axis Ax is away from the second axis Bx.The elastic body 140 of FIGS. 1 and 2 is illustrated as a coil spring,but it is not limited to the coil spring. It can be replaced with otherflexible members as long as they are capable of applying tensions.According to an example embodiment, a base 150 and a movable body 160can be used such that the elastic body 140 applies such a force to themotor shaft 115.

Specifically, the movable body 160 is fixedly coupled to the motor 110and rotatably coupled to the base 150. A specific mechanism for tiltingmotion will be described later in reference to FIG. 4 . Finally, an endof the elastic body 140 is coupled to a point of the base 150, and theother end of the elastic body 140 is coupled to a point of the movablebody 160, which enables the elastic body 140 to be tensioned such as toprovide a biasing force.

As such, based on to an interaction among the movable body 160, the base150 and the elastic body 140, the tension of the timing belt 130applying a force to the motor shaft 115 in a direction towards thesecond axis Bx and the biasing force of the elastic body 140 applying aforce to the motor shaft 115 in a direction away from the second axis Bxare balanced such that the distance between the first axis and thesecond axis is adaptively adjusted.

Referring again to FIG. 2 , an assembly including the pulley 120 and thebracket 170 is rotatably supported on a support member 181 in a lowercase 180 of a housing. For brevity, outer components such as the uppercase of the housing, other than the lower case 180 of the housing, arenot shown in FIGS. 1 and 2 .

As described above, in order to adaptively adjust the position of themotor shaft 115 under the biasing force of the elastic body 140, thebase 150 and the movable body 160 can be used. First, the base 150 isfixed on the housing of the camera assembly 100. Referring to FIG. 2 ,through holes 157 a, 157 b formed on the base 150 may be coupled tocorresponding protrusions 187 a, 187 b formed on the lower case 180 suchthat the base 150 is fixed on the housing. Such protrusions 187 a, 187 bmay be coupled with the through holes 157 a, 157 b by interference fit,but the scope of the disclosure is not limited to the example and otherseparate fasteners can be used as well.

In FIG. 2 , each of the base 150 and the movable body 160 includes ahollow 151, 161, and each hollow 151, 161 is formed at the correspondingposition. In this regard, the motor shaft 115 is disposed to passthrough each hollow 151, 161. Thus, the timing belt 130 is coupled tothe end (e.g. a distal end) of the motor shaft 115 passing through eachhollow 151, 161.

FIG. 3 is a top view of the camera assembly 100 from FIG. 1 , and FIG. 4is a top view showing the base 150, the movable body 160, and elasticbody 140 of the camera assembly 100. Here, the base 150 is fixed on thelower case 180 without relative motion, but the movable body 160 and themotor 110 which are fixedly coupled to each other are configured to turnon a fixed shaft 10 of the base 150 within a predetermined range.

Specifically, the fixed shaft 10 rotatably couples the movable body 160at the first point P1 of the base 150. In this regard, at least onemovable shaft 20 a, 20 b is spaced from the first point P1, coupled tothe base 150 at the second point(s) P2 and received in the correspondingslots 30 a, 30 b on the movable body 160, and supports sliding motion ofthe movable body 160.

According to embodiments, the movable shaft 20 includes two movableshafts 20 a, 20 b, the at least one slot includes two slots 30 a, 30 b,and the two movable shafts 20 a, 20 b are received in the two slots 30a, 30 b, respectively. Two or more movable shafts and slots may be usedto avoid relative shakings which may be generated in a directioncorresponding to the rotation radius R of FIG. 4 in a case where onlyone movable shaft and one slot are used.

When the movable body 160 rotates on the fixed shaft 10, the movableshafts 20 a, 20 b are received in the slots 30 a, 30 b withoutinterference while supporting the sliding motion of the movable body160. To this end, the slots 30 a, 30 b illustrated in FIG. 4 receive themovable shafts 20 a, 20 b, respectively, and are elongated in thecircumferential direction C according to the rotation radius R extendingfrom the first point P1. Thus, even though the movable body 160 rotatesaround the first point P of the base 150 with a predetermined angle,there is no interference between the movable shafts 20 a, 20 b and theslots 30 a, 30 b.

In FIGS. 3 and 4 , a slot(s) is formed on the movable body 160 and amovable shaft(s) is formed on the base 150, but the same function mayalso implemented by the opposite configuration. According to anotherembodiment, a movable shaft(s) may be formed on the movable body 160 atthe second point P2 and received in a corresponding slot(s) on the base150 in order to support the sliding motion of the movable body 160.

Meanwhile, an end of the elastic body 140 is coupled to a latch 165protruded from the movable body 160 and the other end of the elasticbody 140 is coupled to a latch 155 protruded from the base 150. In thisregard, the latch 155 of the base 150 is positioned farther from thesecond axis Bx than the latch 165 of the movable body 160. Thus, whenthe movable body 160 turns clockwise around the first position P1, thatis, the motor shaft 115 moves toward the second axis Bx in the leftdirection of FIG. 4 , the elastic body 140 is stretched to have atension therein. As a result, the tension of the elastic body 140functions as a biasing force to resist the movement and is balanced withthe tension of the timing belt 130. As described above, the elastic body140 is configured to generate the tension as a biasing force between themovable body 160 and the base 150, but the scope of the disclosure isnot limited to this example and the compressive force of the elasticbody 140 can be used as the biasing force as well.

FIG. 5 is a drawing illustrating a connection between the movable body160 and the base 150 according to an embodiment. The through holes 157a, 157 b formed on the base 150 are coupled to the protrusion 187 a, 187b (refer to FIG. 2 ) of the lower case 180. To this end, the throughhole 57 has a clearance around the end of the protrusion 187 a such thatthe end of the protrusion 187 a passing through the through hole 157 adoes not cause any interference. In addition, the protrusion 187 bpassing through the through hole 157 b does not overlap with the movablebody 160 positioned above the base 150 and thus it does not interruptthe movement of the movable body 160.

Next, at least one fastener 40 passes through a through hole 164 formedon the movable body 160 and is coupled with the motor 110 such that themotor 110 is completely fixed on the movable body 160. In addition, ahead 41 (refer to FIG. 8 ) of the at least one fastener 40 is receivedin the through hole 153 having a clearance 154 (refer to FIG. 8 ) withrespect to the base 150, which guarantees a face-to-face contact betweenthe base 150 and the movable body 160 without interrupting the turningmotion of the movable body 160.

Without a through hole 153 with such a clearance, the movable body 160and the base 150 may not completely contact to each other. In addition,without the clearance 154 of the through hole 153, the turning motion ofthe movable body 160 may be interrupted due to interference between thethrough hole 153 and the head 41 of the fastener 40.

Additionally, a through hole 50 of the movable body 160 and a throughhole 55 of the base 150 are used to receive the fixed shaft 10 (refer toFIG. 4 ), and the slots 30 a, 30 b of the movable body 160 and throughholes 35 a, 35 b of the base 150 are used to receive the movable shafts20 a, 20 b (refer to FIG. 4 ). Lastly, the latch 165 formed at a side ofthe movable body 160 and the latch 155 formed at a side of the base 150are connected to respective ends of the elastic body 140.

FIG. 6 is a view of the camera assembly 100 without the lower case 180in the direction E (refer to FIG. 3 ) and FIG. 7 is a longitudinalsectional view taken from the camera assembly 100 of FIG. 6 along thevertical direction.

The motor shaft 115 extends from the motor 110 in the direction alongthe first axis Ax, and a pinion 111 is defined at the end of the motorshaft 115 to be coupled with the timing belt 130. The rotation of thepinion 111 causes the revolution of the timing belt 130 and the pulley120 engaged with the timing belt 130 also rotates accordingly. To thisend, the diameter of the pinion 111 is quite smaller than the diameterof the pulley 120 and a speed reduction and a torque increase aregenerated. The rotation amount of the pulley 120 can be detected by arotation sensor and controlled by a motor controller not shown in thedrawings.

Referring to FIG. 7 , the fixed shaft 10 and the movable shaft 20 areimplemented, for example, by pins and jointly couple the movable body160 rotatably on the base 150. Here, each pin may be installed with nocontact with elements other than the movable body 160 and the base 150.The fixed shaft 10 and the movable shaft 20, more particularly, the headH of the pin defining the fixed shaft 10 may be positioned higher thanthe movable body 160 mounted on the base 150. Thus, even though thefixed shaft 10 is completely coupled to the base 150, the movable body160 is allowed to rotate on the fixed shaft 10 of the base 150.

FIG. 8 is a bottom view of the camera assembly 100 from FIG. 1 without alower case 180. Referring to 8, a pinion 111 is defined at the end ofthe motor shaft 115 forming the first axis Ax, and threads on the innerside of the timing belt 130 engages with the pinion 111. In the sameway, threads 131 on the inner side of the timing belt 130 also engagewith the gear teeth 121 (refer to FIG. 2 ) on the outer circumferentialsurface of the pulley 120.

To this end, the biasing force F1 generated from the elastic body 140installed between the movable body 160 and the base 150, and the tensionT generated in the timing belt 130 are adaptively balanced. Accordingly,even when such a balance is broken for some reasons, the distancebetween the first axis Ax and the second axis Bx is adjusted by itselfand balanced again at another equilibrium point.

For example, in a case where the tension of the timing belt 130 is toohigh, the tension becomes greater than the biasing force F1 of theelastic body 140 and the motor shaft 115 or the first axis Ax movestoward the second axis Bx. Accordingly, the tension T of the timing belt130 would be decreased as a result. On the contrary, in a case where thetension of the timing belt 130 is too low, the tension becomes less thanthe biasing force of the elastic body 140 and the motor shaft 115 or thefirst axis Ax moves away from the second axis Bx. Accordingly, thetension T of the timing belt 130 would be increased as a result. Thus,if the intrinsic bias of the elastic body 140 is set to be a propervalue, the tension of the timing belt 130 would be consistentlymaintained in spite of error factors such as dimensions of componentsand eccentricity caused during an assembling process.

In a specific design, the biasing force F1 of the elastic body 140 canbe estimated from a force balance equation in order to maintain thetension T of the timing belt 130 within a desired range. Assuming thetension of the timing belt 130 is “T” and the reaction force of themotor shaft 115 is “F2”, the following equation 1 is satisfied.

$\begin{matrix}{{F2} = {2 \times T \times {\cos\left( \frac{\theta}{2} \right)}}} & \left\lbrack {{Equation}1} \right\rbrack\end{matrix}$

Here, θ is an angle formed by two parts of the timing belt 130 whichpulls the motor shaft 115.

In addition, “F1” can be expressed by “F2” via a torque balance equationwith reference to the fixed shaft 10, as shown in the following equation2.

$\begin{matrix}{{F1} = \frac{F{2 \times D}2}{D1}} & \left\lbrack {{Equation}2} \right\rbrack\end{matrix}$

By combining the equations 1 and 2, “F1” can be expressed by “T” asshown in the following equation 3.

$\begin{matrix}{{F1} = \frac{{2 \times D}{2 \times T \times {\cos\left( \frac{\theta}{2} \right)}}}{D1}} & \left\lbrack {{Equation}3} \right\rbrack\end{matrix}$

As a result, the biasing force can be estimated, that is, the tension ofthe elastic body 140, based on a designed tension T of the timing belt130 according to the equation 3. According to an example embodiment, thetension T of the timing belt 130 may be equal to or 1.3 times greaterthan the maximum driving power of the motor 110.

According to an embodiment, the camera assembly described above may beassembled by using the following method. Referring to FIGS. 2, 4, and 5again, first, the motor 110 and the movable body 160 are fixedly coupledby the fastener 40 and the movable body 160 is rotatably coupled to thebase 150. To this end, the fixed shaft 10 is coupled to the first pointP1 of the base 150 such that the movable body 160 can be rotatable onthe fixed shaft 10, and the two movable shafts 20 a, 20 b installed onthe base 150 are received in the two slots 30 a, 30 b defined in themovable body 160, respectively. As such, when the motor 110 and themovable body 160 are installed on the base 150, the motor shaft 115extended from the motor 110 passes through both the hollow 161 of themovable body 160 and the hollow 151 of the base 150.

Next, the elastic body 140 is installed such that respective ends of theelastic body 140 are interposed between a point of the movable body 160and another point of the base 150. In addition, the base 150 on whichthe motor 110 and the movable body 160 are installed is fixedly coupledto the housing at some positions (e.g. protrusion 187 a and protrusion187 b).

Lastly, the motor shaft 115, that extends from the motor 110, and thepulley 120 on which the camera module is mounted are coupled in commonby the timing belt 130. As such, when the coupling by the timing belt130 is completed, the tension of the timing belt 130 and the biasingforce from the elastic body 140 become balanced. Specifically, thetension of the timing belt 130 applying a force to the motor shaft 115in a direction towards the second axis Bx and the biasing force of theelastic body 140 applying a force to the motor shaft 115 in a directionaway from the second axis Bx are balanced such that the distance betweenthe first axis and the second axis is adaptively adjusted. Accordingly,the tension applied to timing belt 130 can be adaptively maintainedwithin a designed range.

According to the above embodiments, it is possible to apply a propertension to the timing belt without separate assembling tools andadaptively manage the tension of the timing belt within a designed rangedespite various distributions in the related components.

Additionally, even though there may be a little decentering oreccentricity in some components when installing the camera assembly insite, the tension variation in the timing belt can be minimized and thesame tension can be applied again even after reassembling the cameraassembly.

Embodiments of the present disclosure have been described herein.However, it will be understood by those skilled in the art that variousmodifications may be made without departing from the gist of thedisclosure. Therefore, it is to be understood that the scope of thedisclosure is not limited to the above-mentioned embodiments but isintended to include various modifications and equivalents includedwithin the spirit and scope of the present disclosure.

What is claimed is:
 1. A camera assembly comprising: a motor configuredto generate a driving power; a motor shaft that extends from the motor,such as to define a first axis, and is configured to rotate by thedriving power of the motor; a pulley configured to rotate on a secondaxis, that is spaced from the first axis, according to rotation of themotor shaft; a belt configured to couple the motor shaft and the pulley,and convert the rotation of the motor shaft to rotation of the pulley,and tension of the belt applies a force to the motor shaft in adirection towards the second axis; a camera module configured to bemounted on the pulley and rotate together with the pulley; an elasticbody configured to apply a biasing force to the motor shaft such as tobias the motor shaft in a direction away from the second axis; a baseconfigured to be fixed at a side of a housing of the camera assembly; amovable body configured to be fixedly coupled to the motor and rotatablymounted on the base; a fastener configured to fixedly couple the motorand the movable body, a fixed shaft configured to rotatably mount themovable body on a first point of the base; and at least one movableshaft configured to be coupled to one from among the base and themovable body at a respective second point, that is spaced from the firstpoint, each of the at least one movable shaft received in acorresponding slot in the other from among the base and the movable bodysuch as to support sliding motion of the movable body, wherein thecorresponding slot receives the at least one movable shaft and iselongated in the circumferential direction according to the rotationradius extending from the first point.
 2. The camera assembly of claim1, further comprising: a fixed shaft configured to rotatably mount themovable body on a first point of the base; and at least one movableshaft configured to be coupled to the movable body at a respectivesecond point, that is spaced from the first point, each of the at leastone movable shaft received in a corresponding slot in the base such asto support sliding motion of the movable body.
 3. The camera assembly ofclaim 1, wherein in a case where the movable body rotates around thefixed shaft, the at least one movable shaft is received in thecorresponding slot, without interference from the corresponding slot,while supporting the sliding motion of the movable body.
 4. The cameraassembly of claim 3, wherein the at least one movable shaft comprisestwo movable shafts that are received in a first corresponding slot and asecond corresponding slot, respectively.
 5. The camera assembly of claim1, wherein an end of the elastic body is coupled to the base and anotherend of the elastic body is coupled to the movable body such as to causetension in the elastic body.
 6. The camera assembly of claim 5, whereina point where the end of the elastic body is coupled to the base isfarther than a point where the another end of the elastic body iscoupled to the movable body from the second axis.
 7. The camera assemblyof claim 1, wherein the base has a first hollow and the movable body hasa second hollow axially corresponding to the first hollow, and the motorshaft passes through the first hollow and the second hollow.
 8. Thecamera assembly of claim 7, wherein the belt engages with a distal endof the motor shaft that is passed through the first hollow and thesecond hollow.
 9. The camera assembly of claim 8, wherein a pinion isprovided at the distal end of the motor shaft and gear teeth areprovided at an outer circumferential surface of the pulley, and threadsdefined at an inner surface of the belt engage with the pinion and thegear teeth.
 10. The camera assembly of claim 1, wherein a head of thefixed shaft is positioned higher than the movable body mounted on thebase such as to allow the movable body to rotate around the fixed shaftrelative to the base while the fixed shaft is coupled to the base. 11.The camera assembly of claim 1, further comprising a fastener configuredto fixedly couple the motor and the movable body, wherein a head of thefastener is received in a through hole with a clearance, such as toallow a contact between the base and the movable body withoutinterrupting turning motion of the movable body with respect to thebase.
 12. The camera assembly of claim 1, wherein the at least onemovable shaft is configured to be coupled to the base at the respectivesecond point, that is spaced from the first point, and the correspondingslot is in the movable body.
 13. The camera assembly of claim 1, whereinthe at least one movable shaft is configured to be coupled to themovable body at the respective second point, that is spaced from thefirst point, and the corresponding slot is in the base.
 14. A method forassembling a camera assembly, the method comprising: fixedly coupling amotor to a movable body; rotatably coupling the movable body to a base;installing an elastic body such that two ends of the elastic body areinterposed between the movable body and the base; fixedly mounting thebase on a housing; coupling, using a timing belt, a motor shaft to apulley, the motor shaft extending from the motor and passing through ahollow of the movable body and a hollow of the base, and the pulleyhaving a camera module mounted thereon,; providing a fixed shaft thatrotatably mounts the movable body on a first point of the base; andcoupling at least one movable shaft to one from among the base and themovable body at a respective second point, that is spaced from the firstpoint, and providing each of the at least one movable shaft in acorresponding slot in the other from among the base and the movable bodysuch as to support sliding motion of the movable body, wherein thecorresponding slot receives the at least one movable shaft and iselongated in the circumferential direction according to the rotationradius extending from the first point.
 15. The method of claim 14,further comprising: balancing tension of the timing belt with a biasingforce of the elastic body, wherein the tension of the timing beltapplies a force to the motor shaft in a direction towards a rotationaxis of the pulley, and the biasing force of the elastic body biases themotor shaft in a direction away from the rotation axis of the pulley.